1. Field of the Invention
The present invention relates generally to wrenches specially designed to aid in motor vehicle maintenance, and more particularly, to a wrench especially adapted for removal and replacement of oil filters.
2. Description of the Prior Art
A variety of oil filter wrenches are known in the prior art for aiding the removal and replacement of an oil filter from an engine. For example, the following U.S. patents are known: U.S. Pat Nos. 4,266,452; 4,506,568; 5,024,760; 5,065,648; and U.S. Pat. No. Des. 307,101.
More specifically, U.S. Pat. No. 4,266,452 discloses an oil filter wrench that includes a flexible rubber of plastic sleeve that fits over the oil filter. Gripping between the oil filter sleeve and the oil filter depends upon a wedging action between the sleeve and the oil filter. Such a device has an important drawback. The surfaces of oil filters are often very slippery due to oil leaks from the engine or oil spills on the filter during addition of oil to the crankcase during maintenance operations. In such a case, it may be very difficult to establish a good, non-slipping grip between the sleeve and the oil filter. In this respect, it would be desirable if an oil filter wrench device were provided that did not slip when oil was present on the surface of the oil filter.
U.S. Pat. No. 4,506,568 discloses an oil filter wrench that has a two-part holder structure which has one part nested with the other part. Rotation of the inside part of the holder will lock the ends of the strap to the holder and further rotation of the holder than causes the strap to rotate the oil filter held in the loop of the strap. A significant disadvantage is associated with this the use of this device. Two major parts of the device must be separated from each other during a critical phase in using the device. With separation, there runs the risk of one being dropped or lost at a critical time. Moreover, with two separate devices, one hand would have to be placed on one part, and the other hand would have to be placed on the other part. This can pose a problem when a worker needs the use of one hand to maintain balance. In this respect, it would be desirable if an oil filter wrench device were provided which did not require the user of the device to occupy two hands in manipulating the device.
U.S. Pat. No. 5,024,760 discloses an oil filter that includes unconventional bracket type fins. To use an oil filter wrench would be difficult. The fins would get in the way. In this respect, it would be desirable if an oil filter wrench device were provided that can be successfully used with conventional oil filters and need not be used with special oil filters having bracket fin structures.
U.S. Pat. No. 5,065,648 discloses an oil filter wrench which includes two semi-circular, semi-rigid sections each of which includes a plurality of shark tooth-shaped projections which engage an oil filter of an internal combustion engine. A serious problem associated with the use of this oil filter wrench is that it destroys the oil filter. More specifically, the shark tooth-shaped projections are capable of tearing into and cutting the housing for the oil filter. This means that this device can only be used for removing an oil filter. It cannot be used for installing an oil filter. In this respect, it would be desirable if an oil filter wrench device were provided that can be used for both removing and installing an oil filter. Another problem with this device is oil spillage. When an oil filter housing is punctured during removal of the oil filter from the engine, oil can leak out from the punctured casing and make an oily mess. In this respect, it would be desirable if an oil filter wrench device were provided that did not puncture the oil filter housing and tat did not make an oily mess during oil filter removal.
U.S. Pat. No. Des. 307,101 discloses an oil filter wrench that includes a sequential orderly array of discrete bumps attached to the inside surface of a loop which fits around an oil filter. The size of the bumps indicates that when this oil filter wrench would be applied to an oil filter, there is a serious risk that the oil filter would be undesirably weakened and deformed by the bumps. In this respect, it would be desirable if an oil filter wrench device were provided which did not deform or weaken the oil filter when the oil filter wrench is used.
Aside from the problems stated above, prior art oil filter wrenches have another problem. Generally, oil filter wrenches have to major parts: the filter grabbing part; and the handle. Both the filter grabbing part and the handle are located in the same plane. This means that once the filter grabbing part is applied to the oil filter, the torque that is applied by the handle must be in the same plane as the filter grabbing part. Often, however, the under hood area of a motor vehicle is a quite crowded space, and it is difficult to satisfactorily position the handle in the same plane of the filter grabbing part so that successful application of torque on the handle can take place. In this respect, it would be desirable if an oil filter wrench device were provided that included a handle that could be adjusted to be outside the plane of the filter grabbing part of the wrench. In this way, the wrench would have greater applicability and utility in crowded engine spaces.
Other features would also be desirable in an oil filter wrench. When an oil filter is installed on an engine, there is a specified range of torque at which the oil filter should be installed. Both overtightening and undertightening are to be avoided. In this respect, it would be desirable if an oil filter wrench device were provided that included an indicator that proper torque is applied during installation of the oil filter.
In the close confines of an engine compartment, when using an oil filter wrench, a user's hands may often be injured by either braises or burns. This is especially true of the knuckles of the hand that applies force to the handle of the oil filter wrench. In this respect, it would be desirable if an oil filter wrench device were provided that offered protection to the hand of the user that applies a force to the handle of the wrench.
Thus, while the foregoing body of prior art indicates it to be well known to use oil filter wrenches, the prior art described above does not teach or suggest a oil filter wrench which has the following combination of desirable features: (1) does not slip when oil is present on the surface of the oil filter; (2) does not require the user of the device to occupy two hands in manipulating the device; (3) can be successfully used with conventional oil filters and need not be used with special oil filters having bracket fin structures; (4) can be used for both removing and installing an oil filter; (5) does not puncture the oil filter housing and does not make an oily mess during oil filter removal; (6) does not deform or weaken the oil filter when the oil filter wrench is used; (7) includes a handle that can be adjusted to be outside the plane of the filter grabbing part of the wrench; (8) includes an indicator that indicates when proper torque is applied during installation of the oil filter; and (9) offers protection to the hand of the user that applies a force to the handle of the wrench. The foregoing desired characteristics are provided by the unique oil filter wrench of the present invention as will be made apparent from the following description thereof. Other advantages of the present invention over the prior art also will be rendered evident.